Billy won Best Male Performance at the Critics' Award for Theatre in Scotland 2017 for his role as Willy Loman in Dundee Rep's production of Death of a Salesman. He was also awarded Best Actor in The Stage Awards 2011 for his performance in The Overcoat, which makes him the only performer in the history of the awards to win it twice (he also won in 2009 for his role in The Sound of My Voice).

Television and film credits include: On Falling (Sixteen Films); Only Child (Happy Tramp/BBC); Shetland (ITV); The Farm (BBC); The Crown (Left Bank Pictures); Outlaw King (Netflix/Loudon Productions); Red Hill (Laura Carreira); Rab C Nesbitt (Comedy Unit/BBC); Bob Servant Independent (BBC); Garrow's Law (Shed Productions/BBC); Scottish Killers (STV); The 39 Steps, Hope Springs, Dear Green Place, Empty, Legit, Still Game, Monarch of the Glen (all for BBC); Taggart: Pinnacle, The Royal, Taggart: Sins & Sinners (all for ITV); and Orphaned and Toll (Independent Films).

Theatre credits include: Men Don’t Talk (Genesis TC); Hebridean Treasure (Vision Mechanics); The Celtic Story; The Enemy (National Theatre of Scotland); The 39 Steps; Death of A Salesman; The Cheviot, the Stag and the Black Black Oil; The Resistible Rise of Arturo Ui; Much Ado About Nothing; Little Red and the Wolf; Witness for the Prosecution; Midsummer; The Winter's Tale; Mince and Cabaret (All Dundee Rep); A Streetcar Named Desire (Rapture TC); Flameproof (Traverse Theatre/Oran Mor/Aberdeen Performing Arts); White Gold (Iron Oxide); Now I Am, The Adventures of Robin Hood and The Hunted (all Visible Fictions); Blithe Spirit (Perth Theatre); The Overcoat, Continuous Growth, The Year of the Hare and Preen Back Yer Lugs! (all Ace Productions); Some Other Mother (AJ Taudevin/Glasgow Tron); Skewered Snails (Iron Oxide/London Southbank); A Clockwork Orange, Othello, Ghosts, The Sound of My Voice (winner of 'Best Actor' in The Stage Awards 2009, nominated for CATS Awards 2009), Peter Pan, Hamlet, Wee Fairy Tales, No Mean City and The Twits (all Glasgow Citizens'); Cargo (Iron Oxide); Until It's Gone; Divided; The Scurvy Ridden Whale Man; Flower, Bird, Wind, Moon, Divided; The Book of Love, Short Spin and Wheesht! (all Glasgow Oran Mor); and Look Back in Anger, Virginia Woolf and Romeo and Juliet (Stray Theatre). Billy is also a regular panto Dame!